5p1533

5p15.3 is a cytogenetic band on the short arm of human chromosome 5. In clinical genetics, deletions or rearrangements that include this region are described using the 5p15.3 designation. The string 5p1533 is sometimes seen as a variant or transcription of the same locus, but the standard notation is 5p15.3.

Deletions that encompass 5p15.3 are most notably associated with cri-du-chat syndrome, a condition arising from partial monosomy of the distal portion of chromosome 5. Affected individuals often present with a characteristic high-pitched, cat-like cry in infancy, as well as microcephaly, developmental delay, distinctive facial features, hypotonia, and growth delays. The clinical presentation varies with the size and specific genes affected by the deletion.

Genetically, the critical region for cri-du-chat includes multiple genes, with CTNND2 in or near 5p15.2–5p15.3 being repeatedly implicated in neurodevelopmental aspects of the syndrome. The resulting phenotype is typically due to haploinsufficiency of several genes in the region, rather than a single cause.

Diagnosis is usually made by chromosomal testing, including karyotyping, fluorescence in situ hybridization (FISH), or higher-resolution microarray analysis (array CGH) to map the deletion. Prenatal testing is possible if a parental translocation or a family history is known. Management is supportive and multidisciplinary, focusing on early intervention, developmental therapies, and management of medical issues. The condition was first described in the 1960s and is named for the distinctive cry observed in many affected infants.